Cutting machine



March 7, 1939. G. Av UNGAR CUT-TING MAICHINE Filed Oct. 21, 1955 5Sheets-Sheet 1 R m m v m 31162006 (2, Zlgyar BY ATTORNEY.

March 7, 1939.

G. A. ,UNGAR 2,149,822 cu'r'rme MACHINE I '5 Sheets-Sheet 2 Filed Oct- 21, 1935 ATTORNEY.

G. A. UNGAR CUTTING MACHINE March 7, 1939.

Filed Oct. 21, l35 15 sheets-Sheers INVENTOR. y uiaw Q. Zlzggar ATTORNEY.

G. A. UNGAR CUTTING MACHINE March 7, 1939.

Filed Oct. 21, 1955 5 Sheets-Sheet 5 SH EARING TORQUE CUTTING INTERVAL FRICTION; TORQUE INERTIA TQUE ACCELERATION ANGULAR KNIFE SHAFT POSITIONS- -180 DECELERATlON TORQUE DIAGRAM FOR MAXiMUM CUT-OFF LENGTH INVENTOR.

gushz Ire Q. Zing r' 0 wzEwwz Y ATTORNEY.

Wntented Mar. F, thi h I 2,149,822 a V 1r Macnnm Gustave-A. Ungar, Pelham ma, a. Y., mim- 'ortoS.&8.0om1gatedPaperMachineryCo-,

. N. Y., a corporation oi New pplication mm z1, 1 ss5,.senai No. 45 ,858 r My invention relates to novel cutting apparatus, and, moreparticularly, relates to novel apparatus for and methods of cutting wire and sheet material such as sheetmetal, paper, corru- 5 gated boards, etc. 7 1 I The sheet-material or wire which is to be cut is usually fed at a fixed and constant speed to the cutting apparatus and the cutting apparatus is operated to periodically engage and cut the mam terial. During thecutting pe i d. and while the knives are engaging the material, the knives-hat uraliy must be moving in the same direction and in synchronous speed with the material.

While'the period oi one particular cycle for '15 cutting predetermined lengths of material may be such that the knives are moving in synchronism with the material during cutting. a problem is created when the length of material being cut is changed to a new 'For obtain- 5 ing the new size, the period oi theknife'cyclebe tween cuts is changed to permit more or less material to pass the hives between each cutting operation. In choosing this period of the knife cycle, the rate of speed of the knife at the instant of cutting also changes. so that the knife is no longer in synchronism with the material during cutting. a

Heretoi'ore, it has'been proposed to provide 1 such synchronism for all sizes of cuts byemplcy 9 log in the transmission system which controls the period oi'lthe knife cycle, a complex set of elliptical gears and cams so arranged-that when the drive, speed is changed knives are in synchronism with the movement of the strip material. Besides being costly in that this involved expensive elliptical gears, it also is 40 complicated and not entirely accurate due to the fact that when elliptical gears are used, acertain amount of error in synchronism inevitably creeps in because of the continuous change in speed at every instant which is a characteristic 45 of elliptical gears. This is particularly true in such systems due to the adjustments of the chip tica] gears necessary fol-each size of cut. Al-

though the elliptical gears may be satisfactory when in a predetermined adjustment, they are m not so for a new adjustmentor relative position.

thereof with respect to the knives.

To 'overcome these dllliculties, a radical departure has been proposed in which separate drives for the knives are employed, one for predetermining the period of the cycleoi' the knives or any other type or commonly known transmis- I5 jto'synchronous' speed during cutting. By this 90 I eliminate complicated transmission" mechanlsm, replacing it by simple standard apparatus, but I avoid the diliiculties and inaccuracies practice of the prior artywhich merely changes cutting. for changing the period 01' the knife cycle, a compensating ad- 35 iustment may also be 'made in the elliptical gears and calm so that at the instant of cutting, the.

"mechanism to produce provide a, novel cutting mechanism for sheet ride a novel cutting mechanism for predeterare always in'cutting engagement at the same .the transmission system for controlling the speed 5o provide novel apparatus whereby the cuton.

22mins. (01. 164-58) and which is efl'ective for driving the knives durl.

"ing the non-cutting period and the other for driving the knives during the cutting period at a ,flxed, predetermined speed which is in synsion. I control-this transmission system by an external controlling device which at all times during a cycle acts upon the transmission system for invariably bringing the speed of the knives entirely new principle of operation, not only do experienced by such systems. in that I require 25 only a single control which follows the, common the period of the cycle for diflerent sized cuts desired, the external timing or control mech-. anlsm thereafter functioning automatically to obtain the desired synchronous speed during Four types of such controlmechanism are shown for. modifying thee-speed or the cutting the diflerent cut-'01! lengths ofthe material.

Accordingly, an oblect oi-myinventicn is to material. l I Still another object of my inventionais to 'pro- 40 mined lengths of material.' I r A further object of my invention is to provide a novel cutting mechanism in which the knives speed with which sheet material is fed through themachine.

Another object ofv my invention is to provide a control extending iromand independent of of the'cuttlng mechanism during the ctuitingv Still a further object of my invention is to 7 length, can be readily and quickly modified through selective control at eachinstant in a cycle of a drive connection from a source of power to the cutting mechanism and without the necessity ofclutches or couplings, since the cutting mechanism is always positively driven.

Still another object of my invention is to readily compensate for slight differences between the speed of the material and the speed of the knives at the instant of cutting which may occur,

owing .to a slight slipping of the material between the feed rolls.

Still another object of my invention is to store up the energy of revolving cutting elements when their speed decreases so as to have it available for their acceleration during the other half or the cycle; this eliminates the necessity of braking means which are otherwise required andwhich occasion not only unnecessary power loss 'but also excessive stresses on the driving mechanism.

There are other objects of my invention which, together with the foregoing will appear in the detailed description of the invention which is to follow in connection with the drawings, in which:

Figure 1 is a perspective schematic illustration of one form of my invention.

Figure 2 is a fragmentary side elevation of the speed varying mechanism and transverse section through the master cam employed in Figure 1.

Figure 3 is a perspective schematic illustration of another form of my invention.

Figure 4' is a fragmentary side elevation and Figurefi is a fragmentary longitudinal section of the speed varying mechanism shown in Figure 3.

Figure 6 is a perspective schematic illustration of a further form of my invention.

Figure 7 is a fragmentary side elevation of the speed varying mechanism shown in Figure 6.

Figures 8, 9 and 10 are graphic illustrations of the master cam profiles for the longest, an intermediate and the shortest cut-off length.

Figure 11 is a transverse elevation of still another form of my invention.

. Figure 12 is a fragmentary section along line lZ-IZ in Figure 11.

Figure 13 is aview of the mechanism illustrated in Figure 11 looking in the direction'of arrow l3, while 1 Figure 14 is a view of thesarne mechanism looking in the direction of arrow 16.

Figure 15 is a graphic illustration of the torques of the revolving cutting elements for maximum sheet length during one revolution or cycle.

Referring to Figure l, the feeding roll I, which feeds the sheet 2 in cooperation with spring or weight loaded press r0113, is operated at constant speed by means of sprocket 4, chain 5, and sprocket 6, which is keyed to main drive shaft 1.

Shaft 1 is driven from a suitable source of power. I

- l2, keyed to shaft 13 and through lever I4. Lever I6 is actuated by means of ball joint 15 and turnbuckle l6, i1, i8 from'lever 22. This lever 22 is pressed downward by the action of spring 20, located between the stationary abutment 2| and the pad IS. The upward movement of lever 22 which is keyed to shaft 23 is derived from the movement of lever 25, which is slidably mounted 'on shaft 23 and is driven by means of key 25.

I in Figures 8, 9 and 10, respectively. The axial location of lever 24 determines the cam profile, which is toactuate this lever. The axial shifting of lever 24 to another cam profile is accomplished by-me'ans of link 30, which at its lower forked end 3| engages with groove 32 of lever 24 and at its upper end has a threaded hole 33 with which screw 34 engages. Screw 34 has an extension 35 with a crank 36. By turning crank 36 in either direction, link 30 and with it lever 24, is shifted axially either backward or forward bringing roller 21 into engagement with any desired cam profile 28'.

A' revolving knife carrier31 to which is attached a suitable knife or cutter 38 and timing gear 33 is also keyed to shaft 29. This is in meshing engagement with timlng gear 40 which is keyed to lower knife shaft 4| which has attached to it knife carrier 42 with its knife 43. Shaft 6| is driven from output shaft 46 of the variable speed transmission by means of sprocket '45, chain 44 and sprocket 43'.

Knife shafts 31 and M are driven at continually varying velocities, which, at each angular position of the knives, are derived from a corresponding positlon of the cam profile 28 with which roller 21 and lever 24 are cooperating.

The position of cam profile 23', shown in full lines in Figure 2, corresponds to the knife position shown in Figure 1. At this point of the cycle, the knife carriers 31 and 43 have the lowest angular velocity for the sheet length in question, while in the dotted position (cam profile 28"), the knife carriers 31 and 43 move at maximum angular velocity, with knives 38 and 43 in cutting engagement at a speed equal to the constant speed of sheet 2. This speed variation is ,produced by the back and forward shift of belt 8 by means of fork "l, which in turn is oscillated by the movement of lever 24.

The momentary contact radii of cam 28 with roller 21 are inversely proportional to the variable speed of shaft 46, since the variable speed of this type of transmission varies in linear proportion with the axial location of the belt shifting mechanism. I

It will be seen from the following that the cam drum 28, when driven at constant surface velocity, will complete one revolution in a time directly proportional'to mean radius of cam profile 28 and any desired length of sheet can be cut off and accurately duplicated, as long as lever 24 remains in the same axial position relative to the cam drum 28. The various cam profiles, some of which are shown in Figures 8, 9 and 10 all have a cam portion consisting of a circular segment with the same radius r0 extending over the same angular distance. As long as roller 21 is in contact with this cam portion To, lever 24 produces the maximum output speed of the variable speed transmission and the knives 38 and 43, which are then in cutting engagement, are always moving at the same velocity as the sheet while in cutting engagement, regardless of which cam profile actuates lever 26.

Assuming L to be the desired cut-off length m:v

the sheet, '0 the veiocitywith which the sheet is fed into the apparatus and T the time which elapses between consecutive cut-oils, then we Assuming v to be constant, a increase or decrease of T produces a proportionate increase or decrease of L.

By changing the revolutions minute of the knife shaft, T can be varied. if this change would take place with constant angular velocity during. the entire knife cycle, then the material and the knives would not move st the some speed while the cut takes place, and the materiel would there fore tear or buckle. The knife shalt velocity must therefore be varied so that it is equal to that oi the sheet while the out is mode.

Now if the angular dispiscement or travel of the knife shaft and therefore of the com drum is represented in radlens, by 9, the variable cam drum radius by r, and the time by t, the variable angular velocity w of the cam in rsdlans per second can be written as Wan With the cam driven at constant circumierential velocity and therefore operating at s. variable angular velocity, to which is inversely proportional to the contact radius r of the earn from which the variable speed W is controlled, we-can write:

rw=lc where it is s constant depending upo the input velocity of the veriuble s :3: 118- sion and the gear ratio between the output shaft of the variable transmission and the knife Sh t Y Therefore cr ree .The time T for one complete revolution or the. cum and therelore the knife shalt can he es:

L=rrr if r-es pre by represents the mean cam radius ment of 360.

It is theretore only nry to shift lever 2d axially to any desired cum profile, in order to ob tain a cut-ofi lengthot the sheet, which is di rectly proportional to the meun rudius oi the cam in question.

To obtain a speed of the knives during the'pe riod oi cutting, eduul to thet oi the sheet 1?, it is now only necessary to select a cum radius 7'0 which through its action upon the vshle smed transmission produces at that moment the de= sired knife speed c. The remoininu rodii n: or the cams can then be chosen th due regard to obtaining the most satisfactory acceleration and deceleration conditions tor the revolving is shafts t1 and ti, so long as the mean cam us producing the desired cut-od length-remains unchanged.

The operstion oi the hnliic shfits is, therefore,

continuous and they are ulways driven tively location of lever Maud without the necessity of 5 any clutches, brakes, elliptic gears, etc.

In order to correct any slight speed differences between the sheet and the knives when they ere cutting owing to possible shifting of the sheet between the feeding rolls 6 and 8, the relative 10 positions of lever 2d and belt shifter fork item be readily changed. This is done by means of turnbuckle it, ll, 08 which shortens or lengthens the linkage between levers Maud 22.

If the knives move too fast at the cutting in- 15 stunt, shifter fork it is moved to the right and conseuuently the output speed of drum ll ls'reduced during the entire cutting cycle, until sheet and knife speeds are equol at cutting. The cutoil length has been slightly increased and to keep gm the cut-oil length the same as before, it is only necessary to shift lever lit to the left until the correct length is again cut-oh by operating hundle fit. This, of course, does not change the knife velocity during the cut-oil period since all earns 25 have the same radius to for the cut-0d.-

Another embodiment of my invention is shown in a perspective schematic view in Figure 3.

The principal difierence from the first modification consists in the einotion of the sepaon rate variable speed trunsmission-by utilizing the cam drum as a frictional variable speed drive.

Main drive shaft ill, which. operates at constant speed, has keyed to it sprocket d8. Through chain ill it drives sprocket td, keyed to feed roll v shaft ill, which carries ieed roll b2 and feeds the moterial at constant speed through the cooperstion with spring loaded press roll ht.

Main drive shsit ll has extending over its ontirelength a. key t l, which drives the crown pulley m its slidsbiy mounted upon shell; ll. (See also Figures d and 5.) Crown pulley lid has a hub extension with two ring grooves t6 and ti. Groove he provides the bearing for swing arm be,

, which at its upper end carries stud ht. The exn g tension to of stud 59 fo the bearing for idler crownpulleyfil, which is driven at constant speed by belt 6? from pulley tit.

it ttis pressed against the periphery of cam constant peripheral s, since the belt sd is constant.

The cam drum (it is keyed to shaft M, which "also carries timing gear t5 and the lower knife.

ins gear tt is in. mesh with timing gear dd, keyed to ur knife carrier st withkniie t'l.

shaft ts which operates mule csrrier lid with its kn fe ll The consecutive profiles of cam d or correspond to those shown in Figures 8, 9 and 10, proor I file it corresponding to that of Figure B, profile it to thst of Figure it, while profile it (Fig. 4), -which represents the intermediate cam with which belt 52 is shown in contact with Figure 3 The mean rsdli of theverious sums are again proportional to the cut-0d lens of the material, since the ansularvelocities at each pointof the cum in contact with belt, t2 are inversely prooorresponds to that of Figure 9. up I portional to the contest rudius oi the r m v In the position'of cum ti shown in Figure 3, and in full lines as it in Figure 4, the wives are at their slowest angular velocity. th the 'cam' in Figure i, in dotted position it" and belt and pulley (in dotted lines) in tions 82' and ti'f l drum til, which is thewiore made to revolve at "respectively, the knii'eshaft 88 is driven lat maxisince the knives 81 and II are engagement.

Belt 62 is kept guiderod 18. This guide rod 'ld'has as its lower end fulcrum pin I1, which is'mounted in'shifter l l8. Shifter I8 has any extension 18' which formsf a bearing for groove 51 of crown pulley'55. At

' its upp r end guide rod I8 slides in extension 80 of stud 58. Extension" also forms the upper abutment for spring I while at its'lower end it bears against shoulder 8| which carries pin Tl.

Shifter l0 can-be moved axially along the entire length of cam drum 83 through the action of screw 82, which engages, with screw threads 1 83 of shifter 18 by turning crank 88.

Belt 82 together with swing arm 58 is moved outward, thereby compressing spring as the cam radius increases with decreasing angular cam velocity and it is kept in contact withthe' cam as the cam radius decreases because of the action of spring I5. I I The sheet cut-ofl length can therefore be varied at will, between desired limits, while the machine is in motion and is accurately maintained by merely shifting the belt 82 axially and withoutanyother speed changing and without drive engaging and disengaging mechanism, since the knife shafts are always driven at therequiredvelocity' by thefrictional engagement between belt and cam drum.

A third embodiment of my invention is shown as.perspective schematic view in Figure 6. r

This alternative diflers from the previous one by having gears of various diameters in engagement with a constant speed drive gear; substituted for the cam drum profiles which are in frictional engagement with the constant speed belt. o Main drive shaft 88 drivesat constant speed,

through gears 88, 8'! and shaft 88, sprocket 88, chain 80 and sprocket 8|, the feedingroll shaft 82, which has keyed onto it lower feeding roll 88; The material is fed at constant speed through the cooperation between roll 83 and spring or weight loaded feeding roll 88.

Main drive shaft 85 has an extended key'85.

which drives, slidably mounted upon shaft85, the sprocket 88 with its hub extensions 81 and 81'. The outside of hub 81 forms a bearing for rocker arm 88 which at its upper end carries journaled with it, shaft 88. This shaft is driven from sprocket 88 by means of chain I00 which drives sprocket IOI keyed to shaft 88." Gear I02 is also keyed to shaft 88 and it drives with constant pitch line velocity any of the gears I03 with which The mean pitch radius of each gear I03 is proportional to a definite cut-ofi length of the sheet. The profiles of the pitch lines correspond to the cam profiles of the two previous embodiments of my invention. Since the angular veloc- I itles of the gears I03 vary in inverse ratio with I the contact radii of gears I03, the cut-off length produced by each gear is proportional to the mean pitch radius of each gear. The longest cut-ofl is produced with drive gear I02 in mesh with I03. Its pitchline profile 'is the same as cam profile Figure. 8. The shortest cut-off is produced when I02 meshes with gear I 03', the pitchline profile of which corresponds to earn profile Figure 10.

in cohanudunictibni an: tact with'cam drum 83 through thc actio'n of compression spring '18, which is coiled around I 'The pitchiine profile of an intermediate gear mum velocity, corresponding to the sheet velocity, then in cutting I03" corresponds to cam profile Figure 10.

- In order to maintain the gears in mesh, rocker arm 88 oscillates back and forward and tooth cohtactis maintained by the action of'compression spring I00 which is guided by bar I05. The

upper end of bar I05 is pivoted on shaft 88 while its lower end is slidably mounted in guide I08, *if whiehispivotedlon pin I01. Pin I0! is mounted gin shifter fork I08 which engages with groove I08 on; the hub 81 of sprocket 88.

Shifter fork I 08 is slideably mounted on bar if] I 0, E'ach meshing position of gear I02 with the different gears I03 is definitely secured by lock pin II I mounted slideable in a hole in shifter fork I08, dropping into engagement with one of the holes H2 in bar H0. Lock pin III is Journaled at H2 in hand-lever I I3. By pushing lever I I3 downward and thereby compressing spring H4, lockpin .III is lifted out of engagement with one of the holes 2 and shifter fork I08 can now be moved axially until lockpin III drops into another hole II2.

In order to make it impossible to attempt any shifting of drive gear I02 axially, unless it is in mesh with that portion of all cam gears I03, I03 and I03" whichis represented by the equal radius m in Figures 8, 9 and 10, rocker arm 88 is provided with a, projection H5. This projection II5 engages with one of the slots II8 of register bar I II where the rocker arm 88 is not in the position which produces meshing of gear I02 with the cam gear portion having the radius To. Rocker arm 88 can then not be shifted axially which prevents any possible damage to the gear teeth owing to clashing or loss of tooth engagement. The dotted position in Figure 7 indicated by I03', I02, 88' and H5 show the mechanism at the moment of lowest angular velocity of the driven gears I03. In this position no gearshifting is possible. I I

with rocker arm 88 in the full line position shown in Figure 7, gear I02 can readily be shifted axially, since the teeth of all profile sections with radius T0 are now perfectly in line.

Gears I03 are keyed to lower knife shaft H8 which carries timing gear H8 and knife carrier case it is only necessary to revolve the knife shafts until drive gear I02 meshes with the minimum radius'sector T of the cam gears. I

A fourth and preferred embodiment is shown 'in Figures 11, 12, 13 and 14.

The whole mechanism is here mounted in frame members H8, 8', I20, I2l. The power source is shown .to be. an electric motor I22, which operates at certain constant rates of speed to produce certain definite constant feeding ve-' locities of the sheet material, directly proportional to the motor speed.

Motor I22 drives through pulley. I28 and belt I24, the pulley I25 which is keyed to the input shaft I26 of a variable speed hydraulic pumpmotor unit I21. This unit may be any of the standard types such as a hydraulic transmission,

148, gears I41 and I45.

described in the Journal of the American Society of Naval Engineers, volume 44; (XLIV); 1932 pp. 25-27. These consist of a multiple cylinder oil pump of variable displacement driven at constant speed from a power source, such as I22, and which delivers the oil to a multiple cylinder hydraulic motor, thereby driving it at'a variable speed proportional to the variable displacement of the oil pump. The variation of the pump displacementis accomplished by changing the piston stroke through a suitable mechanism.

vSuch a mechanism consists for instance with the Oiigear" of a stubshaft attached to a cross slide for shifting the relative locations of the crankshaft to the cylinder block, with the cylinders in star formation. By changing the rela-.

tive crankshaft'location the stroke'of the pump cylinders and with Jitthe output of the pump is changed.

In Figure 14, the stubshaft for changing the pump stroke is indicated by I28. In the position shown. the pump hasits maximum stroke and therefore maximum output producing maximum speed of the hydraulic motor and with it its shaft extension I28. The pump volume and of variable speed unit m is sprocket m, which drives lower feeding roll I88 through chain I84, sprocket I85and gears I88 and I81. The sheet I88 is fed into the machine in thedirection of arrow I88 by feeding roll I88 in cooperation with spring or weight loaded press roll I. v

The variable speed output shaft I28 of the transmission I21 is connected to jackshaft-lfl by coupling I42 and drives the lower knife shaft I48 by means of sprocket 4, chain I45, sprocket Keyed to lower knife shaft rier I58 with knife I 5I. Gear I48 drives gear I58 keyed to the upper knife shaft I52 which has keyed toit knife carrier I54 with knife 155.. .Lower knife shaft I48 has keyed onto it cam cam drum I58 through the action of stubshaft I28 and spring ISI.

Rocker arm I58 is also axially slidable on shaft I88 which it oscillates by means of key I88.

I58 can be moved axially by means of shifter fork I84 which engages with groove I58 in the hubof arm I58. Shifter fork I84 has a hub I85- which forms the nut for a shifting screw I88, journaled in frame H8 at I51 and in frame 8' in I88. Handwheel I88 operates screw I88.

The rocking motion of arm I58 is transmitted to stubshaft I28 as follows: Lever I18 is keyed to rocker shaft I88 and is connected to lever auassa m is knife car- I88, which actuates stubshaft I28 is also keyed to shaft I11.

The various profiles of. cam drum I55"corre-.

spond to those disclosed in the previously described embodiments of my invention, profile I58 corresponding to that of Figure 8, while profile I58" correspondsto that of Figure 10.

The mean radii of the various cams'ar'e again proportional to the various cut-off lengths of the material. since the angular velocities of-shaft I49 for each point of cam contact with roller I51 are inversely proportional the contact radius of the cam. Each position of rocker arm I58 produces a definite output speed of the variable speed unit I21 and since, as pointed out before,

this speed variation is in direct proportion to the movement of stubshaft m, the output speed of unit m and with it the knife shaft speed therefore varies in inverse ratio to the contact radius of roller I51 with cam I55. The cut-oil length is therefore definitely controlled by the axial location of rocker arm I58. Any desired 'length of cut-oil within certain limits can be accurately regulated and definitely maintained without variation. The cut-oi! length adjust- .ment canbe made with the mechanism in operation at'any desired speed or at rest since the hydraulic unit can be regulated equally well be readily adjusted by changing the relative positions of rocker arm I58 and stubshaft I28 by means of turnbuckle I12, I18, I14. If the knives move too fast during their cutting engagement,- the distance between I" and I15 is lengthened bygmeans' of they turnbuckle. This moves lever I88 and stubshaft I28 to the right, thereby re-. ducing the output speed of the transmission and with it the knife speed. Since this-speed reduction affects the entire cycle, the cut-off length has been increased, because the feeding velocity The last described embodiment of my-inven tion also illustrates a special arrangement to compensate the considerable acceleration and deceleration forces which are present with revolving shafts of variable angular velocity, and which otherwise require additional driving power during the acceleration period and braking means during the deceleration period.

This arrangement consists in storing the inertia torque of the mechanism during the deceleration period so as to have it available during the acceleration period. The mechanism subsequently described is, of course, equally applicable to the other disclosed embodiments of my invention; I

Upper knife shaft I52 has an eccentric or crank This eccentric portion I18 actuates connecting rod I18, which engages atits upper end with rocker arm I88, which has itsfulcrum at I8I in a bracket.

I82 located on frame I2I'. Rocker arm extension I88, rests on spring fulcrum I84, holding compression spring I85 at its upper end while spring portion I18 located between frames I2I' and I28.

. arm I58.

In the position of eccentric I18 shown in Figures 12, 13 and 14, spring I85 is at minimum compression, and knives I5I and I55 are then in cutting engagement at maximum angular velocity. As knife shaft I52 continues to revolve in the direction of the arrow, its angular velocity decreases, with a resultant deceleration force. This deceleration force or torque is counteracted by the force necessary to compress spring I85, which is thereby storing up or accumulating potential energy until connectingrod has reached its top position, when the knife shaft reaches its lowest angular velocity. As the knife shaft continues to turn, it has to be accelerated again and this acceleration is now assisted by stored energy from the previously compressed spring I85, which now exerts a torque on the knife shafts in the direction of the drive.

Figure 15 shows a torque diagram for the maximum cut-off length, plotted against the angular positions of the knife shaft over 360. As positive torques are plotted the friction torques of the machine, which increase slightly with increasing angular knife shaft velocities, and the shearing or cutting torque which is only required during the cutting period. The deceleration torque is plotted in negative direction and it becomes practically fully available as positive torque for acceleration. It is, therefore, quite evident that the arrangement of this torque accumulator eliminates the necessity of using braking means to take care of deceleration forces and at the same time greatly reduces or entirely eliminates power consumption otherwise required for acwleration.

By substituting a cam and follower mechanism for the eccentric I18 and connecting rod I19 it is possible to modify the character of the inertia torque curve so as to obtain the most satisfactory acceleration and deceleration conditions of the knife shafts, by employing an appropriate cam profile. Since acceleration and deceleration forces decrease with decreasingacut-off lengths, the required tension of spring I85 will also be less. The adjustment of this spring tension for different cut-01f lengths as above described can be either manually by handwheel I84 or by adjusting means interlocked with the mechanism for regulating the cut-off length. The tension of spring I85 can also be changed with variations in the speed of the main power source I22, so as to vary the rate of feed and therefore output of the machine. during deceleration and made available for acceleration changes with the square of the operating speed of the machine, and the tension of the torque accumulator spring I85 to take care of this can either be manually by handwheel I89 or automatically by suitably linking the spring compression means to the speed controlling means of power source I22.

It is also apparent that the torque accumulating mechanism may employ other elastic means in place of the coil spring I85 which is illustrated. Such other elastic means may be rubber blocks or compressed air cushions,.wit h and with- The inertia torque to be stored.

out the intermediate insertion of a hydraulic column. 7

Although I have described preferred illustrations of my invention, I do not intend to be limited thereby except as set forth in the appended claims.

I claim:

1. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a timing element having a variable contour from one end thereof to the other; a. common means coacting with the several parts of said variable contour for selectively controlling the period of an associated cycle of the cutting mechanism and also controlling the rate of rotation of said cutting mechanism during cutting.

2. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a timing element comprising a camelement having increased camming effect from one end to the other, said cam element controlling the period of a cycle of the cutting mechanism and also controlling the rate of rotation of said cutting mechanism during cutting.

3. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a Reeves drive for driving said cutting mechanism; a timing element having a plurality of timing sections; a common means cooperating with each section independently controlling the operation of said Reeves drive for controlling the period of a cycle of the cutting mechanism and also controlling the rate of rotation of said cutting mechanism during cutting.

4. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism and for driving said cutting mechanism; and timing means directly operable on said power means, means cooperating with said timing means for varying the cycle in which said power means drives said cutting mechanism and invariably driving said cutting mechanism at the speed of said strip material during cutting.

5. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at constant speed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a velocity controlling means exterior of said driving connection for selectively controlling the velocity at which said driving connection drives said cutting mechanism throughout the cycle.

6. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at constant speed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a velocity controlling means exterior of said driving connection for selectively varying the period of thecycle at which said driving connection drives said cutting mechanism and for causing said driving power to drive said cutting mechanism in syncbronous speed with said strip material during the cutting interval.

7. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at constantspeed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a velocity controlling means exterior of said driving connection for selectively controlling the velocity at each instant in a cycle at which said driving connection drives said cutting mechanism throughout the cycle.

8. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at constant speed past said cutting. mechanism; a driving connection from said power means to said cutting mechanism; and a timing means exterior of said driving connection for selectively varying the rate at every instant of the period of the cycle at which said driving connection drives said cutting mechanism and for causing said driving power to drive said cutting mechanism in synchronous speed with said strip material during the cutting interval.

9. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a timing means comprising a cam mechanism having a surface varying in contour continuously from one end to the other; a cam follower; means for selectively bringing said cam follower in operative relation with one of said contours and a connection from said cam follower to said driving connection for controlling the rate at which said driving connection drives said cutting mechanism.

10. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; and a constant speed drive connection from said power means to said cutting mechanism comprising solelycircular driving connections and means for varying the time cycle at which said cutting mechanism is operated from saidsource of power while maintaining said constant speed and for maintaining said cutting mechanism in synchronism with said strip material during the cutting period.

11. Ina device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a driving connection and timing mechanism for said cutting mechanism comprising a hydraulic transmission unit for driving said cutting mechanism in synchronism with said strip material. 1

12. In a device for cutting strip material in predetennined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cutting mechanism; a continuously operating positive driving connection from said power means to said cutting vmechanism; and a velocity controlling means exterior of said driving connection for selectively controlling the velocity at which said driving connection drives said cutting mechanism throughout the cycle.

13. In a device for cutting strip material in predetermined lengths; cutting mechanism onerable in cycles; power means for feeding said.

strip material at constant speed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a timing means exterior of said driving connection for varying the period of the cycle at which said driving connection drives said cutting mechanism and for causing said driving power to drive said cutting mechanism in synchronous speed with said strip material during the cutting interval; and means for compensating for any tendency to a slight difference between the speed of the cutting mechanism and strip material at the period of cutting.

14. In a device for cutting strip material in predetermined lengths; cutting mechanism oper- 7 predetermined'lengths; cutting mechanism operable in cycles; power means for feeding said strip material at a constant speed past said cut ting mechanism; means for increasing .the speed of the cutting mechanism to the speed of the strip material for cutting operation; means for decreasing the speed of the cutting mechanism in accordance with a desired time cycle; means for compensating for slight differences in speed between the cutting mechanism and strip material which tend to occur at the cutting period; and means for storing energy during the period of decreasing speed of the cutting mechanism for use during the increasing speed period.-

16. In a device for cutting strip material in predetermined lengths; rotary cutting mecha nism operable in cycles; power means for feeding said strip material at constant speed past said rotary cutting mechanism; a driving connection from said power means to said rotary cutting mechanism; and a velocity controlling means eX- terior of said driving connection for selectively controlling the velocity at which said driving connection drives said rotary cutting mechanism throughout. the cycle.

17. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means for feeding said strip material at constant speed past said cutting mechanism; a driving connection from said power means to said cutting mechanism; and a timing means comprising a plurality of elliptical gears; a driving connection from said elliptical gears to said source of power; means for selectively switching said driving connection to any one of said gears forcontrolling the rate at which said driving connection drives said cutting mechanism. g

18. In a device for cutting strip material in predetermined lengths; cutting mechanism operable in cycles; power means ior feeding said strip material at a constant speed past said cutting mechanism; a source of power; and a driving connection from said source of power to said cutting mechanism comprising a cam, the con- 19. In a device for cutting strip material in predetermined lengths, cutting mechanism operable in cycles; power means; a drive connection from said power means to said cutting mechanism; means for feeding said strip material past said cutting mechanism at a constant speed; and means exterior of said. drive connection for selectively controlling said drive connection to vary the speed at which said powermeans drives said cutting mechanism.

20. In a device for cutting strip material in' predetermined lengths, cutting mechanism operable in cycles; power means; a drive connection from said power means to said cutting mechanism; means for feeding said strip material past said cutting mechanism at a constant speed; and

predetermined. lengths. cutting mechanism operable in cycles; power means rotating at a relatively constant speed; a drive connection from said power means to said cutting mechanism; means for feeding said strip material past said cutting mechanism at a constant speed; and adiustable means exterior of said drive connection for selectively controlling said drive connection to vary the speed at which said power means drives said cutting mechanism whereby strip material of variable lengths is cut.

22. In a device for cutting strip material-in predetermined lengths, cutting mechanism operable in cycles; power means operating at substantially constant speed; a drive connection from said power means to said cutting mechanism; and means for selectively varying the speed at which said cutting mechanism is driven by said power means while permitting said power means to remain operating at said substantially constant speed.

GUBTAVE A. UNGAR. 

